The prior art is already aware of ground trenchers which are mobilized and thus move along the ground while a trencher boom is vertically positioned for digging into the ground and forming the trench therein. These prior art trenchers commonly include ground wheels for mobilizing the trencher and they include a type of powered drive, such as a gasoline engine, for powering the digging chain and for driving traction wheels or other means which induce movement or which mobilize the entire trencher. One example of one type of prior art trencher is seen in U.S. Pat. No. 2,997,276 wherein there are three ground wheels and there is a winch for pulling the trencher along the desired ground line while the digging chain enters the ground and forms the trench and a side-mounted auger moves the dug-up ground away from the trench.
The present invention is concerned with the mobilized support and balance and reactive forces of the trencher, and it will of course be understood that when the trencher chain is digging in the ground, the chain creates a reactive force on the remainder of the trencher, and the ground-supporting wheels should resist that reactive force in order to have the trencher remain upstanding and steerable along the desired trench line on the ground. That is, in the prior art trenchers, the force of the digging chain on the remainder of the trencher is commonly sufficient to cause one or more of the trencher traction wheels to be urged upwardly and lose traction and impair the stability and the steering of the trencher along the ground. In those undesirable instances relative to the prior art trenchers, the operator must endeavor to resist the reactive force by holding on to handle bars or the like in order to prevent the trencher from tipping over or at least prevent the traction ground wheel from losing traction with the ground. In prior art trenchers where the operator must hold the trencher against the aforesaid reactive forces, the steering of the trencher is a problem, and the trencher boom and chain tend to bind in the trench, due to the tipping tendency and the steering problem.
Accordingly, in the present invention, the aforesaid problem is recognized and identified, and the solution to the problem is in the provision of a trencher which overcomes the aforesaid traction, tipping, steering, and like concerns experienced with the prior art trenchers.
Specifically, the present invention is an improvement upon the prior art trenchers in that it has recognized the aforesaid problems, and the present invention provides a trencher which has offset traction wheels disposed in the optimum position on the trencher for the purpose of mobilizing, ground driving, steering, and totally balancing the trencher. In accomplishing these objectives, the trencher of the present invention arranges the traction wheels in axially offset positions, and a releasable type of caster wheel is also provided all for accomplishing the aforesaid objectives and overcoming the problems of the prior art. In doing so, the attention, effort, and skill normally required from the operator are all reduced and the trencher can be operated in a rapid manner and with a most desirable formation of a trench.
Other objects and advantages will become apparent upon reading the following description in the light of the accompanying drawings.